Eating a tomato every day of the week reduces your risk of suffering the blues by 52 per cent, according to a new study.

Doctors think it’s because tomatoes can protect you from an assortment of diseases – including heart attacks and cancer – which can trigger depression in sufferers.

Analysing the diets and mental health of 1,000 over 70s in Japan, the study showed those eating at least two tomatoes a week were happier.

While researchers cannot be sure lycopene – which gives tomatoes their deep red colour – directly affects the mind, eating other healthy foods like cabbage, carrots and pumpkins has no effect on psychological well-being. A fifth of us will suffer depression at some time and the elderly are at high-risk from declining health, bereavements and loneliness.

The research was led by Dr Kaijun Niu from China’s Tianjin Medical University, and published yesterday in the Journal of Affective Disorders.